1. Field of the Invention
The present invention relates to systems and methods for spacecraft navigation and control, and in particular to a system and method for determining the attitude of spacecraft payloads.
2. Description of the Related Art
Satellites and other spacecraft often include multiple payloads, one or more of which can have high-precision pointing requirements. The attitude of the spacecraft can be accurately derived using data obtained from a plurality of different attitude sensors, such as gyros, earth-limb sensors, sun sensors, and star sensors. However, even if the nominal attitude of the payload relative to the spacecraft is known apriori, actual payload attitude cannot be accurately derived in many cases due to deviations from the nominal spacecraft-payload interface. Such deviations can be caused, for example, by payload thermal deformation which occurs as the spacecraft orbits the Earth.
What is needed is a system and method that permits the accurate determination of the attitude of spacecraft payloads, even when subject to payload thermal deformation. What is also needed is that the system and method be implemented at a minimal cost to spacecraft computer throughput and memory.
The present invention satisfies that need.